VULNERABILITY INTELLIGENCE
CVE-2026-42557
CVSS score9.6 CRITICAL
EPSS probability0.49%
CISA KEVNot currently listed
Published2026-05-13
Last modified2026-10-25
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Description
jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. Prior to 4.5.7, JupyterLab's HTML sanitizer allowlists data-commandlinker-command and data-commandlinker-args on button elements, while CommandLinker listens for all click events on document.body and executes the named command without checking whether the element came from trusted JupyterLab UI. A notebook with a pre-saved HTML cell output containing a deceptive button can trigger arbitrary JupyterLab commands - including arbitrary code execution - on a single user click, without any code being submitted for execution by the user. This vulnerability is fixed in 4.5.7.
Weakness classification
- security-advisories@github.com: CWE-79
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c: CWE-79